A conventional smartphone enables its user to access a variety of electronic resources. Examples of such resources includes a cellular telephone, messaging apps, a camera, the Internet, email, social media apps and games, among others.
To access such resources, the user typically authenticates by entering a password (e.g., a sequence of four numbers) on the touchscreen of the smartphone. If the entered password matches an expected password, the smartphone unlocks—thus enabling the user to access the resources. Additionally, the smartphone may re-lock after a period of smartphone inactivity, preventing further access to the resources.